Legal Commentary: The ability of the owner, whose data was reconstructed, to get relief to under copyright would depend upon what exactly the training data was. In the United States, facts are not copyrightable, even if they are costly or time-consuming to gather. Copyright protection may attach to compilations or arrangements of factual information, however, it is unlikely that a reconstructed set of training data would necessarily share the same compilation or arrangement as the original: for instance, the reconstructed data could be approximations as in the case of [1]}. So the owner of the dataset/model would be unlikely to be able to successfully sue an adversary that recovered part of a training dataset consisting of facts for copyright infringement.
